Most of central Bobo can be walked. From the cathedral to the Grande Mosquée is twenty minutes on foot, and the markets, museum, and Place de la Nation are all within that radius. Beyond the centre, the easiest option is a shared taxi (taxi-brousse) for a few hundred CFA, or a moto-taxi which costs about the same and is faster through traffic. Both work on negotiated fares — confirm the price before you get in.
Renting a car is rarely necessary unless you plan to range outside the city. For Dafra and Koro, hire a taxi for the half day with a guide; expect to pay around 15,000–25,000 CFA. The roads in town are uneven; mind your ankles at night.